Application of hottest servo control system in hea

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Application of servo control system in heat shrinkable film packaging machine (Part 1)

key words: heat shrinkable film packaging machine acopos servo color film

at present, various brands of beer rush into the market first, and various beer manufacturers are constantly improving the quality and output of beer in order to seize business opportunities. Therefore, the renewal of the original old beer production equipment has become a factor that the medical industry has always been the main business of Solvay for beer manufacturers to consider. In the production of beer, from the beginning of brewing, filling, sterilization to the final labeling and packaging, every production link is related to the final beer output. The high degree of automation makes packaging a weak link in the whole beer production for a long time. Foreign heat shrinkable film packaging machines (hereinafter referred to as film packaging machines) have been able to complete the final beer packaging, such as Italy dymac, SMI, ocme, Germany Krones. Due to the high price of foreign film wrapping machines, many domestic beer manufacturers have used low-cost collective manual bundling or simple manipulator moving as the way of beer packing, especially in the form of collective manual bundling. In this way, a large number of bottled beer produced in the first few links will accumulate to the end, making the first few production links often slow down due to the final slow manual binding. In addition, the occasional burst of bottled beer often hurts the staff who are carrying out the bundling operation. In June, 2002, China clearly stipulated in the new GB beer standard that manual strapping packaging should be banned. After learning from the advanced concepts of foreign film wrapping machines, several domestic light industrial machinery manufacturers and other beer production equipment manufacturers have also launched domestic film wrapping machines according to the market demand

system configuration and scheme

generally speaking, the film wrapping machine is composed of six parts: main drive, bottle feeding, bottle separating, paper feeding, film feeding and cutting, and hot channel. According to different design ideas, the mechanical structure of the coating machine produced by various manufacturers is different, and the programmable control system and servo control system selected are also different. Taking the capsule machine of keshimin company as an example, this paper will introduce the bergalay programmable control (PCC) system and servo control (acopos) system as the control part

The servo control system with synchronous electronic gears and electronic cams has long replaced the cumbersome mechanical cam mechanism, which can easily realize the synchronous relationship between moving objects according to the requirements of designers. Several motion mechanisms of the film wrapping machine use the servo motor as the drive shaft to complete the tasks from bottle feeding, paperboard feeding to film cutting. The main drive using one servo motor will be used as the synchronization object of several other axes, and all the angle and phase relations are also determined according to the main drive motor. Figure 1 shows the approximate position of the five motors in the machine

Figure 1: the position of the motor in the machine

control system

using the servo control system of baccalais can fully meet the basic motion control of all motors of the capsule machine and the synchronous motion control between them. The man-machine panel pp41, which integrates the logic control in the packaging process and has the display function, on the one hand, can convey commands and motion characteristic parameters to the motion control part through the input of parameters, on the other hand, it can timely feed back the current machine operation status and alarm status

· field bus (CANbus)

can bus has strong error detection ability and differential drive function, and it still works well in a very harsh environment with strong noise. Therefore, in terms of media transmission and line design, can bus can be easily suitable for most applications

through the fieldbus, the communication between the man-machine panel (pp41) and each servo controller becomes very reliable, especially for the modification of synchronous characteristic parameters in the servo motion control system

Figure 2: communication between fieldbus, man-machine interface and servo controller

· basic motion control

baccalais' servo motion control system (acopos servo) adopts an object-oriented control mode. Using high-level language (basic or C), after creating an axis object for a servo controller, you can use the created pointer to complete different motion control of the motor

Status=ncaction(AxisBUR- Object,ncPOS_MOVE,ncSTART);

procedure 1

function ncaction (due to the large deformation of rubber tensile testing machine during stretching) will execute all basic operation commands for servo motor motion control. Parameter 1 is the pointer of the moving control object, parameter 2 is the control mode of the moving object, and parameter 3 is the action behavior facing the control mode. The meaning of the above statement is: let the moving object axisbur object move ncpos in the positive direction_ Move, ncstart start start

basic motion control will be used for the independent commissioning and parameter seeking of each motor of the film wrapping machine, the start and stop of the main drive, and the cooperation of the bottle splitting motor. This control method has clear objectives and is convenient for the preparation of control procedures

· synchronous motion control

synchronous motion control is the control of a servo motor to complete a certain motion trajectory relative to another servo motor according to a certain mathematical model, which is commonly referred to as the concept of electronic gear and electronic cam

for acopos servo, the two servo motors involved in synchronization have a master-slave relationship and a long construction cycle. The synchronous motion control of the film wrapping machine is generally synchronous in position. On the CAN bus, the spindle will transmit the current position information to the can network with a certain micro fixture mechanism: according to the small interval of the tested product, and the slave shaft participating in the synchronization will also obtain these information in real time, and then calculate the current slave shaft position according to the mathematical model in real time, and run the current trajectory

through the mathematical model, we can get the profiler of the slave axis relative to the main axis. The characteristic parameters of these contours should be downloaded to the servo controller before the motor participates in the synchronization. Pp41 will use can bus to download parameters. Acopos servo can set 11 sets of contour relationships at a time, and use the event method to make the slave axis jump conveniently according to the needs of movement in the set contour relationship group. There are many kinds of trigger events. Pp41 can be used to send down four signal messages (ncsignal1.2.3.4) or two trigger messages on the servo controller (nctrigger1.2). Therefore, we can decompose the master-slave contour relationship into several stages (States) according to certain requirements. Through the jump between stages, we can complete the synchronization requirements of different stages

in the film wrapping machine, after receiving the film feeding signal, the film feeding motor starts to move synchronously when the main motor runs to a certain phase again until the main motor completes a cycle, and the film feeding motor also completes a film feeding task. We can divide it into three stages, that is, the film loading motor waits for the film loading signal, the main motor reaches the film loading start phase, and follows the main motor to complete a film loading task. When applying film, the last stage can be subdivided into several stages according to the principle of "slow before fast"

· virtual axis concept

in acopos servo, the moving object created for each servo motor has an imaginary axis, that is, the virtual axis. This virtual axis is the same as the real axis. On the one hand, it can be used as a slave axis to complete the synchronization track with the main axis. On the other hand, it can also be used as a main axis to allow other slave axes to participate in the synchronization. Due to the introduction of the concept of virtual axis, a servo motor can also synchronize with its own virtual axis

if a main virtual axis is added between the film loading motor and the main motor, the contour relationship of the three stages of waiting for the film loading signal, waiting for the starting phase of the main motor, and completing a cycle with the main motor can be added to the main virtual axis. The film motor can be synchronized with the main virtual axis to complete the synchronization tasks of several stages from slow to fast. In this way, when the main motor does not move, let the virtual axis go for a cycle, and the film feeding motor can complete the film feeding task once, that is, manually apply the film once, which is convenient for the front and back adjustment of the film feeding position at the beginning

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